Ubuntu Pro Live Patching Compatibility with Custom DKMS Modules on 22.04 LTS

Ubuntu Pro Live Patching and DKMS Module Compatibility

Ubuntu 22.04 LTS with Ubuntu Pro offers kernel live patching that allows applying security fixes without rebooting. This feature is particularly valuable for maintaining application continuity during patch cycles. However, the interaction between live-patched kernels and third-party DKMS modules presents a potential compatibility boundary.

When Ubuntu Pro applies live patches, the kernel version string remains unchanged, which generally preserves compatibility with userspace binaries. The caution around DKMS modules stems from the fact that these modules are compiled against specific kernel headers and symbol tables. If a live patch modifies kernel symbols or structures that a DKMS module depends on, the module may fail to load or cause system instability.

The specific constraint is determining which DKMS modules are compatible with live-patched kernels and whether additional steps are required to maintain their functionality. This becomes critical for applications that depend on custom kernel modules built via DKMS.

Key questions:

• Which specific conditions or module types are known to be incompatible with Ubuntu Pro live patching?
• What verification procedures should be followed before enabling live patching on systems with DKMS modules?
• Does Ubuntu Pro provide any tooling or documentation to assess DKMS module compatibility with live patches?